Line- and spotplating machine

ABSTRACT

Apparatus for continuously plating metal on a metal strip including a plating wheel defining an electrolysis chamber with an annular slot opening at the periphery thereof, an anode mounted on the plating wheel in the electrolysis chamber, a closed system for supplying electrolyte to the electrolysis chamber, and a shoulder on the periphery of the wheel to receive a metal strip to be plated, the metal strip closing at least a portion of the slot opening to define a wall of the electrolysis chamber and functioning as a cathode such that the metal strip has a metal pattern plated on the side supported on the shoulder.

United States Patent [191 Meuldijk et al.

[ LINE- AND SPOTPLATING MACHINE [75] Inventors: Pieter W. Meuldijk, Vught; Ben J.

Roodnat, s-Hertogenbosch, both of Netherlands [73] Assignee: Meco Metal Finishing Engineers N.V., s-Hertogenbosch, Netherlands [22] Filed: May 25, 1972 [21] Appl. No.: 256,847

[30] Foreign Application Priority Data [58] Field of Search 204/15, 28, 206, 207, 224 R, 204/275, DlG. 7

[ June 25, 1974 3,468,785 9/1969 Polichette 204/224 R 3,537,971 11/1270 Green 204/28 3,539,490 11/1970 Gannoe 204/28 FOREIGN PATENTS OR APPLICATIONS 1,098,182 1/1968 Great Britain 204/15 Primary Examinerl-loward S. Williams Assistant Examiner-W. 1. Solomon Attorney, Agent, or Firm-Sherman and Shalloway [5 7] ABSTRACT Apparatus for continuously plating metal on a metal strip including a plating wheel defining an electrolysis chamber with an annular slot opening at the periphery thereof, an anode mounted on the plating wheel in the electrolysis chamber, a closed system for supplying electrolyte to the electrolysis chamber, and a shoulder on the periphery of the wheel to receive a metal strip to be plated, the metal strip closing at least a portion of the slot opening to define a wall of the electrolysis chamber and functioning as a cathode such that the [56] References Cited UNITED STATES PATENTS metal strip has a metal pattern plated on the side supported on the shoulder. 2,591,042 4/1952 Berman et a1. 204/206 3,152,977 10/1964 Bartholomew et a1 204/224 R 23 Claims, 15 Drawing Figures o 7 a f 7 1 7 W 1 1 42 1.3 211 1.1. 1 ll; 39 1s PATENTED JUN251974 SHEEI 2 OF 8 PATENIEDJIINZSW 3,819,502

SHEU 3 OF 8 PATENTED JUN25 i974 SHEU S [If 8 1 LINE- AND SPOTPLATING MACHINE This invention relates to an apparatus for continuous plating of line or spot patterns particularly of precious metal on metal strips.

In the electronic industry frequent use is made of gold plated components such as semi-conductors, connectors etc. For a number of these parts functional or partial gold plating would be sufficient because the functional area is usually only a part of the total component. Particularly in the case of certain connectors as used for contacting printed circuits boards and for semiconductors devices partial plating would be sufficient.

Gold is used because (a) it has excellent corrosion resistance, (b) it has very good electrical properties, (c) it can be easily cold-welded and soldered, etc. A good corrosion-resistance guarantees a long existance of properties named under (b) and (c). To avoid excessive use of costly gold metal, methods have been developed by certain companies for functional plating. In many cases, however, such methods increase labor costs dramatically. Particularly connectors and certain types of semi-conductors are manufactured from stripmetal e.g. brass, phosphorbronze, nickel silver etc. Such stripmaterial is usually up to 100 mm wide and between 0,1 and 1 mm thick. If such a material could be provided with a gold line in such a way that during the stamping operation of the component the gold would be exactly on the functional area, an important saving of costly gold could be obtained. Such material is commercially available under names as rolled gold, double or walz gold.

These known materials are manufactured by rolling a strip of gold on to a base material. Heat treatments and further rolling results in the final product with one or more lines of gold on the strip. This known technique has two main disadvantages, l very often thickness tolerances are very large, in general it is difficult to obtain thicknesses of less than 5p, whereby a tolerance between 5p and 8 is quite normal while for many electronic applications the requirements are not more than 0.5 2p, and 2) insufficient purity: gold as a pure metal (24 Carats) is very soft (VH 60-70) and normally unsuitable for direct use without addition of other metals.

Normal additions are silver, copper and nickel. To obtain a suitable material addition of 25 percent is normally required (purity of gold 18 Ct. hardness 150-220 HV) such that the gold metal loses part of its desired properties and, of primary concern, loses the required consistancy of these properties.

Electroplating of gold offers the possibility to obtain similar properties of hardness and wear resistance with co-deposition of only minor amounts of other metals (0.1 1 percent). It is even possible to obtain hardnesses of 300 VH with gold with a min. purity of 99.99 percent.

Moreover electroplating can be applied in any desired thickness.

Until recently stripes have been electroplated with gold all over.

The purpose of the invention is to provide an apparatus for plating lines or spots on metal strips in a continuous way. The complete apparatus includes, as usual in electroplating, of a pre-treatment sequence, in which it is also possible to apply thin undercoatings. Such undercoatings of the entire strip nickel is the most preferred metal for this purpose have a dual function. They avoid diffusion of gold into the base material, and corrosion of those parts of the strips which are not goldplated.

The invention provides an apparatus of a type as mentioned above with'the characteristic that the apparatus has a plating wheel including sides defining an electrolysis chamber which discharges in a slot at the periphery of the wheel, which slot has at least a portion thereof closed by a strip on which the metal pattern is to be plated, said strip covering a part of the circumference of the wheel and being transported with a certain velocity and hence driving the wheel, whereby there are a suitable electrolyte and an anode in said electrolysis chamber and whereby the strip serves as a cathode, with the result that when leaving the circumference of the wheel the strip will be coated with the desired metal pattern on that side which has been previously engaged with the wheel.

To obtain complete leakproof engagement of the strip against the circumference of the wheel the apparatus is also provided with a tension regulator which guarantees leakproof engagement of every type of a strip on to the wheel.

The advantages of the apparatus of this invention are:

a. a large flexibility in strip width and thickness b. an equally large flexibility in line width and pattern and location of these patterns or lines c. a very high deposition speed by means of a special agitation system d. a large variation in gold thicknesses and a very accurate and constant thickness of the electroplated metal e. the possibility of using undercoatings to avoid diffusion.

The apparatus of the invention as hitherto described has been designed for electroplating metal patterns on a full metal strip which logically closes the circular electrolysis chamber entirely. The apparatus in this condition is not suitable for plating patterns on perforated strips because the electrolyte of the electrolysis chamber would flow away through the perforations in the metal strip. The present invention has also for its object to provide means for plating perforated metal strips e.g. pre-stamped strips for the manufacturing of contacts or integrated circuits, and provides for that reason an apparatus for continuously plating of line-or spot metal patterns in particular precious metal on metal strips, which apparatus has a wheel in which an electrolysis chamber, which discharges into a slot in the circumference of the wheel or into a perforated rim, can be covered over a part of the circumference of the wheel by the strip on which the metal pattern must be plated, which strip engages with a part of the circumfer'ence of the wheel and is transported at a certain velocity and so drives the wheel, whereby there are a suitable electrolyte and an anode inside the electrolysis chamber, and whereby the strip acts as cathode with the result that said strip on leaving the wheel will be plated with the desired metal pattern on that side which has been previously engaged with the wheel, with the improvement that the apparatus for electroplating perforated metal strip has also an endless carrier band which is lead over a number of rollers and is in engagement with the same or a smaller part of the circumference of the wheel than the metal strip tobe plated, and presses against that side of the metal strip which is not against the wheel, which carrier band, at least at the side which is against the metal strip, is made of elastic material and in this way creates leakproof closing of the electrolysis chamber.

In this improved apparatus prevention of leakage of solution from the electrolysis chamber is secured by the metal strip to be plated, and additionally by a carrier band at the outside. In the preferred construction an additional apparatus for applying tension to the carrier band is provided; this mechanical tension provides a leakproof engagement of carrier band and metal strip. Because many pre-stamped strips carry delicate patterns, pulling of such strips could easily damage the parts. Instead of driving the strip itself, in this alternative situation the carrier band can be driven. Supply and discharge of the metal strip itself can be achieved then with minimum load.

This carrier band is preferably made from a base material which is strong and has low elasticity, coated with a top layer of elastic material. It is evident that the carrier band will be used in such a way that the elastic coating is engaged with the perforated metal strip.

Most perforated metal strips carry index or pilot holes which are stamped together with the pattern and it is sometimes desired that the carrier band has equal perforation, whilst the wheel must always be provided with identical reference pins, guaranteeing correct positioning of spots on metal strips during spot plating.

It is clear that when a perforated metal strip must be spotplated, use could be made also of the apparatus first described by using an elastic mold or mask between the circumference of the wheel and the metal strip. However, perforated metal strips in many circumstances very delicate and easily deformed resulting in insufficient strength of the threelayer system of mold,

' metal strip and carrier band, through which it is possible that the assembly will be drawn partly inside the slot in the circumference of the wheel. Hence there is a risk of leakage.

Similarly, as described before the electrolysis wheel includes two rings which can rotate on a stationary shaft on bearings spaced at a certain distance, which rings also enclose the ring-shaped electrolysis chamber and, as a further extension of the invention, one of these rings has nearby its circumference an axial rim which is also attached to the edge of the other ring, said rim carrying the metal strip to be plated and having a number of holes which define the discontinuous slot and function as the mask or mold, and determine shape and location of the metal spots to be plated on to the strip. This rim forms a sufficiently strong base for the perforated metal strip and the carrier band. It is evident that the outside of the rim should be made of elastic material to prevent leakage.

The carrier band will be wetted through the perforations in the metal strip with electrolyte and hence can wet the metal strip to be plated at the back side and form substitution stains on said metal strip when it comes anew in contact with the backside of the metal strip. To prevent this, particularly when the metal to be plated is gold and hence costly, it is preferred to use a rinsing stage through which the carrier band runs after having served its purpose and before it is reused.

The invention will be more readily understood by reference to' the accompanying detailed description and drawings, in which FIG. 1 is a schematic view of the complete plating unit,

FIG. 2 is a schematic side view of the apparatus of FIG. 1 embodying the present invention,

FIG. 3 is a view, partly sectioned through line III-III over the electrolysis wheel used in FIG. 2,

F IG. 4 is a view partly sectioned through line IVIV over the wheel of FIG. 3,

FIG. 5 is a view of a piece of strip plated with a gold line with the apparatus according to this invention,

FIG. 6 is an illustration of the mold with which spots can be plated instead of a continuous line,

FIG. 7 is a section through line VII-VII of FIG. 1 over an adjustable tension regulator which controls the tension in the metal strip,

FIG. 8 is a partial section similar to FIG. 6 showing a variation of the apparatus of this invention for the application of two metal lines simultaneously,

FIG. 9 shows a schematic sideview of the apparatus of this invention FIGS. 10a and 10b show a section and topview, respectively, of the carrier band,

FIG. 11 is a section along line III-III of FIG. 9,

FIG. 12 is a side view and partially a section of the wheel of FIG. 11,

FIG. 13 is a partial section along the line VV of FIG. 12 and FIG. 14 is a top view of the perforated metal strip which hasbeen plated with gold spots with the apparatus of this invention.

FIG. 1 shows the entire electroplating apparatus. On the decoiling structure 42 is a stock of strip 4 to be plated. This strip runs through an adjustable tension regulator 43, a pre-treatment section 44, the apparatus of this invention 1, an after-treatment section 45, a drive unit 46 with variable speed control, including a socalled S-roll, which pulls the strip without slip, a second adjustable tension regulator 47 which controls the tension under which the plated strip 4 will be coiled on reeling apparatus 48. The heart of this electroplating apparatus is shown in FIG. 2. This apparatus mainly comprises an electrolysis plating wheel 1 over the circumference of which the pre-treated and now partially to be plated strip 4 is lead by means of two guiding rollers 37 and 38. The strip 4 is transported in the direction of the arrow and drives wheel 1 which is partially mounted in tank 18 containing the electrolyte 5. This electrolyte is transported through pipe 21 by pump 19 through the filter and heat exchanger 20 and further through pipe 22 and valve 41 to wheel 1 from which it flows through holes 17 back into tank 18. Wheel 1 must be placed above the level of the electrolyte in tank 18. Tank 18 is placed on the structure 39; wheel 1, electrolyte tank 18 and structure 39 are firmly attached to the floor. FIG. 3 shows the section of the shaft of wheel 1, of FIG. 2, along the line IIIIII. On the stationary shaft 10, the supports of which are not further indicated, two ring members 8 and 9 are positioned in a revolving situation. Ring 8 has bearings with ring 26, which has an L-shaped section, and with ring 28, which rings are positioned by nut 31 on shaft 10. Ring 9 has a bearing on ring 27, which has an L-shaped section, and also in a disc-shaped ring 29, which rings are positioned by nut 32. The two flat rings 28 and 29 hold between them the electrolysis distributor 23. The complete assembly is fixed on shaft by ridge on shaft 10. When assembling the apparatus, so far described, the electrolysis distributor 23, is first pushed on the shaft against ridge 30 after which ring 29, ring 9 and finally ring 27 are mounted, after which the total assembly is fixed by means of nut 32.

After this, from the other side ring 28, ring 8 and ring 26 are positioned and fixed by means of nut 31. In the construction of FIG. 3 all parts are stationary with the exception of the rings 8 and 9 with the adjustment and leakage preventing elements 35, 36, ll, l3, l4 and 12, which are driven by strip 4.

To the circumference of rings 8 and 9 adjustment rings 11 and 12 are attached, with the axial position thereof being adjustable by screws and separation bushings 36. The smallest distance between the two adjustment rings 11 and 12 is exactly the same as the width of strip 4. This strip 4 engages or seats on shoulders of rings 8 and 9 with a leakproof, fluid-tight seal and hence forms a wall of the electrolysis chamber 2 by means of the leakage preventing elements such as annulus sealing members 13 and 14, which can be made e.g. from O-rings which are partially grounded flat. The width of the gold line plated on strip 4 is determined by the smallest distance between the leakage preventing elements 13 and 14. Because both adjustment rings 11 and 12 can be independently adjusted by using bushings 36 with the correct length, the location of line 7 (see FIG. 5) on strip 4 can be selected as desired. The width of this strip depends upon the thickness of disks 28 and 29 which controls the slot width 3 and of which a number should be present to enable a large variation in width.

As it appears from FIG. 3 the width of the slot 3 at the outside of the wheel, ie at the side adjacent to the strip 4, is larger than at the inner side, i.e. the side oriented towards the electrolysis chamber 2. Thereby the edges of the metal pattern to be deposited is somewhat screened by the material of the rings 8 and 9, so that an accelerated metal deposition at said edges is counteracted and a uniform layer thickness is achieved.

The electrolysis chamber 2 is formed by the two rings 8 and 9 and in this electrolysis chamber 2 an anode is positioned in the form of an isoluble platinum plated titanium strip annulus 6 having a large number of small holes therein and, functions therefore also as an electrolysis distributor. Anode 6 is connected to the titanium wire 25, shown in the upper portion of FIG. 3, and wire 25 extends through the slot between ring 27 and 28 to the exterior.

It is, however, also possible to use an anode such as metal pellets in two anode compartments attached to the sides of distributor 23 in which case the outside of the electrolysis distributor 23 should be of plastic.

In order to obtain an excellent distribution of the electrolyte electrolysis distributor 23 is provided with a number of radial channels 24 defined by radially extending ribs. The electrolyte 5 is supplied to the wheel through pipe 22 (see also FIG. 2) from which it flows into the interior 33 of shaft 10. Where the electrolysis distributor 23 is in communication with shaft 10, radial channels 34 are present enabling the electrolyte to flow into the circular space between shaft 10 and the inside of the electrolysis distributor. From this ringshaped space 40 the electrolyte flows through radial channels 24 in the electrolysis distributor 23 and through the perforations in the electrolysis distributor- /anode 6 with force into the ring-shaped electrolysis chamber 2 against strip 4, from which it overflows through perforations 17 in rings 8 and 9.

This flow of electrolyte has been indicated in FIG. 3 with arrows.

The level of the electrolyte in chamber 2 is controlled by the position of valve 41 (see FIG. 2). The thickness of the electroplated stripes 7 can be adjusted by means of the speed of strip 4, the concentration of the electrolyte 5, and the current as supplied by the source of current (not indicated in drawing) to which anode 6 and strip 4 acting as a cathode are connected.

The positioning of the anode, and the injection system with respect to the strip allows an extremely rapid metal deposition.

The adjustment rings 11 and 12 enclose strip 4 in such a way that it is impossible that electrolyte overflowing through hole 17 along the outside of rings 8 and 9 could reach the backside of strip 4 with the effect that the strip will remain dry at that side, and that no metal deposition will take place. When spotplating of strip 4 is desired instead of the continuous line the leakage preventing elements 13 and 14 are replaced by a leakage preventing mold 15, as shown in FIG. 6, which carries strip 4. Strip will then only be plated at the location of the holes 16 in the mold.

It is advantageous to construct all parts of the electrolysis wheel, with the exception of anode 6 and titanium wire 25, of a transparent material, e.g. a polymethylmethacrylate, such as Perspex, which enables adjustment of the level of the electrolyte (see FIG. 2) in the electrolysis chamber with great accuracy by means of valve 41. Another good material for construction of parts is a high molecular polyethylene, such as RCH 1000 which has a low coefficient of expansion and can be used for machined parts with high tolerance.

It is evident that when strip 4 must be plated with several parallel lines of the same or different materials the strip can be lead successively over separate apparatus in succession of which adjustment rings 11 and 12 being so positioned that each successive pattern is plated on the desired location. If required, patterns can be plated on top of each other. If, however, the uncoated area between two parallel plated stripes is larger than 5 mm a rim ring 53 can be introduced between rings 8 and 9, as shown in FIG. 8, adjustable on threaded bars 56 between rings 8 and 9, and carrying at its circumference, one or more leakage preventing elements 54 and 55. Such a rim ring 53 does not prevent free flowing of the electrolyte and can be positioned on bars 56 at any desired place. Very wide strips can be plated with several rim rings with more than two stripes in one operation.

In FIG 7, a section is shown of the tension regulator 43 of FIG. 1. Strip 4 is guided in the regulator over three rollers, the two top ones, of which one 50 is visible, having a fixed position in frame 51, while the lower roller 49 can move vertically in frame 51.

The lower movable roller 49 is drawn downward by cable 52 running over a number of guiding wheels and weight G with an adjustable force. The mechanical tension in the strip is therefore in direct relation to the size of weight G. Roller 49 actuates two limit switches which control the drive motor of decoiling apparatus 42, see FIG. 1: in the top position of roller 49 the motor is switched on and in the lower position the motor is switched off.

The temporary rigid combination of leakage preventing elements and the strip result in a hitherto unknown sharp line definition of the metal patterns. As shown in FIG. 9 the strip 1 to be plated, comes from a pretreatment line not indicated in the drawing towards the first roller 37, then over the actual electrolysis wheel 1 and continues over the second guiding roller 38 towards an after-treatment sequence which again is not indicated. Pre-treatment and after-treatment are no part of this invention and are for this reason not shown. The electrolysis wheel 1 is again rotable on the shaft, placed in the tank 18, containing electrolyte 5. The electrolyte is drawn from this tank 5 through the suction pipe 21 by the pump 19 and transported through the filter/heat exchanger 20 and, valve 41 to the inside of shaft 11 into the electrolysis wheel 1 after which the electrolyte 5 overflows through the holes 17 in the sides of wheel 1 in tank 18. The level L of the electrolyte within the wheel 1 is controlled by valve 41 and is visible from the outside due to wheel 1 being made of a transparant non-conducting material.

Tank 18 is mounted on the frame 39 which is attached to the floor. The metal strip 4 is transported in the direction of the arrow and drives the electrolysis wheel 1.

Because metal strip 4 in this case is perforated, as shown in FIG. 14, the prevention of leakage from the electrolysis chamber is obtained by means of carrier band 58 which is lead over four guiding rollers 60 up till 63 and driven by the revolving electrolysis wheel 1 itself. The carrier band 58 is kept under tension by a regulator assembly 64 including a pivotally mounted arm 66 carrying a pressure roller 68 at one end and an adjustment weight 70 at the other end.

In FlGS. a and 10b a section and a topview of the carrier band 58 are shown. FIG. 10a shows carrier band 58 as constructed with a non-expandable base layer 72 and an elastic top layer 74, the latter layer contacting metal strip 4 during operation. Because the elastic side 74 of the carrier band is wetted with electrolyte through the perforations in metal strip 4, this could lead to formation of metal stains on the back side of metal strip 4. To avoid this, FIG. 9 shows a rinse assembly 76 which cleans the carrier band 58 before re-use.

FIG. 11 shows a section of electrolysis wheel 1, again assembled over the stationary shaft 10 with an interior space 33. On this shaft 10, two rings 78 and 80 are mounted on bearings, each of these rings rotating in an L-shaped ring 26, 27 on a flat disk 28, 29, respectively. Disks 28 and 29 are fixed together by nuts 31, 32.

Between the two inner rings 27, 28 an electrolysis distributor 23 having jets 82 is located, the jets operating as an anode. This anode 82 is connected by means of titanium wire 25 through holes in rings 27, 29 to a source of current. The electrolyte 5 is fed through the interior of shaft 10, the radial channels in the electrolysis distributor 23, and the jets 82 into the electrolysis chamber 2, and the electrolyte leaves the chamber again through holes 17 in rings 78, 80.

The two rings 78, 80 are in this case not independently revolving, but ring 78 carries a rim 84 which is attached to ring 80 by bolts 46. This rim 84 carries a number of holes 88 which control the shape and position of the metal spots to be plated on the perforated metal strip 1.

On the outside of rim of the wheel is an elastic material 90, and at both sides of this rim, rings 78, are provided with pilot pins 92, 94 which engage with pilot holes 96 in metal strip 4, as shown in FIGS. 13 and 14. Also carrier band 58 can, if desired, carry reference holes 98, as shown in FIG. 10!).

FIG. 14 shows an example of the perforated metal strip in topview which can be plated automatically and continuously with spots in a machine of this invention. Such strips are frequently used for the manufacture of integrated circuits and the strip supplies in this way the conductors which only require functional gold plating. The plated areas are indicated in FIG. 14 by dotted squares 100.

We claim:

1. Apparatus for continuously plating metal on a metal strip comprising a plating wheel having sides defining an electrolysis chamber with an annular slot opening at the periphery of said wheel, anode means mounted on said plating wheel in said electrolysis chamber, electrolyte means supplied in said electrolysis chamber, shoulder means carried on the periphery of said wheel, and transport means supplying a metal strip to be plated to said wheel, said metal strip being sup ported on said shoulder means to close at least a portion of said slot opening to define a wall of said electrolysis chamber, said metal strip being connected as a cathode, said plating wheel including a shaft having an axis about which said wheel rotates, an electrolyte distributor including a ring-shaped chamber surrounding said shaft and a plurality of radial channels communicating with said ring-shaped chamber and with said electrolysis chamber, and jet means disposed at the point where said radial channels communicate with said electrolysis chamber for distributing said electrolyte in jets in said electrolysis chamber.

2. The apparatus as recited in claim 1 wherein said transport means includes means upstream of said plating wheel for regulating the tension on said metal strip.

3. The apparatus as recited in claim 1 wherein a titanium wire is connected with said anode means and extends through said plating wheel.

4. The apparatus as recited in claim 1 wherein said plating wheel is made of a transparent material.

5. The apparatus as recited in claim 1 wherein said anode means is an annular platinum plated titanium annulus disposed at the point where said radial channels communicate with said electrolysis chamber.

6. The apparatus as recited in claim 5 wherein said anode annulus has a plurality of holes therein forming jet means for said electrolyte.

7. The apparatus as recited in claim 1 wherein said transport means includes a plurality of rollers and an endless carrier band engaging and carrying said metal strip and arranged around said rollers, said carrier band guiding said metal strip into engagement with said shoulder means to close at least said portion of said slot opening, and the side of said carrier band engaging said metal strip being made of an elastic material to prevent leakage from said electrolysis chamber.

8. The apparatus as recited in claim 7 wherein said transport means includes means for regulating the tension on said carrier band.

9. The apparatus as recited in claim 7 wherein said carrier band is made of a non-expandable backing coated with a layer of elastic material.

10. The apparatus as recited in claim 7 wherein said transport means includes a drive roller rotated by a speed regulated motor to permit minimum tension on said metal strip.

11. The apparatus as recited in claim 7 wherein said transport means includes cleaning means for rinsing said carrier band after said carrier band leaves said plating wheel to remove electrolyte therefrom.

l2. The apparatus as recited in claim 7 wherein said plating wheel includes a stationary shaft, first and second ring members mounted on bearings on said stationary shaft in spaced relation, a peripheral rim portion of said first ring member being attached to said second ring member, said rim portion having a plurality of holes therein to define said slot opening discontinuously to function as a mask for plating the metal pattern on said metal strip.

13. The apparatus as recited in claim 10 wherein said shoulder means has indexing pins extending therefrom and said carrier band and said metal strip have holes therein to receive said indexing pins.

14. The apparatus as recited in claim 13 wherein said rim portion of said first ring member is made of an elastic material.

15. The apparatus as recited in claim 1 wherein said plating wheel includes a stationary shaft and said sides include a pair of ring members mounted on hearings on said shaft in spaced relation, the space between said rings defining said electrolysis chamber and said slot opening at the periphery of said rings.

16. The apparatus as recited in claim 15 wherein said plating wheel includes a rim ring disposed between said ring members at the periphery thereof, said shoulder means and said rim ring carrying annular sealing members to form a pair of openings to permit plating of two metal patterns simultaneously.

17. The apparatus as recited in claim 15 wherein said shaft has a bore therein and a plurality of radial holes communicating with said bore, said ring members include radially extending ribs defining a ring-shaped chamber around said shaft communicating with said radial holes and defining a plurality of radial channels communicating with said ringshaped chambers and said electrolysis chamber, said ring members having discharge holes therein and said electrolyte means includes tank means disposed below said plating wheel to collect electrolyte, filtering and heating exchanging means, and supply means including a pump and valve means to controllably force a fluid electrolyte from said tank means through said filtering and heat exchanging means, said bore, said radial holes in said shaft, said ring-shaped chamber, said radial channels, said electrolysis chamber and said discharge holes to said tank means whereby the supply of electrolyte to said electrolysis chamber is continuously replenished.

18. The apparatus as recited in claim 15 wherein said slot opening is radially outwardly tapered such that the width of said slot is greater adjacent said shoulder means to screen the edges of the plated metal pattern by said ring members whereby the plated metal pattern has a uniform thickness.

19. The apparatus as recited in claim 15 wherein said plating wheel includes a pair of adjustment rings each carried by one of said ring members, said adjustment rings being axially adjustable along said shaft to determine the location on said metal strip of the metal pattern to be plated and to permit plating of metal strips of varying widths.

20. The apparatus as recited in claim 19 wherein said plating wheel includes a ring-like mold element made of elastic nonconductive material and having a plurality of holes therein, said mold element engaging said metal strip and said shoulder means whereby a spotted metal pattern can be plated on said metal strip.

21. The apparatus as recited in claim 19 wherein said adjustment rings are disposed adjacent said shoulder means to seat said metal strip on said shoulder means in fluid tight relation to seal said slot opening.

22. The apparatus as recited in claim 21 wherein said adjustment rings each have a bevelled edge slanting toward said slot opening to seat said metal strip on said shoulder means.

23. The apparatus as recited in claim 21 wherein said shoulder means carries annular sealing members around the periphery of said wheel on either side of said slot opening to determine the width of the metal pattern to be plated on said metal strip. 

1. Apparatus for continuously plating metal on a metal strip comprising a plating wheel having sides defining an electrolysis chamber with an annular slot opening at the periphery of said wheel, anode means mounted on said plating wheel in said electrolysis chamber, electrolyte means supplied in said electrolysis chamber, shoulder means carried on the periphery of said wheel, and transport means supplying a metal strip to be plated to said wheel, said metal strip being supported on said shoulder means to close at least a portion of said slot opening to define a wall of said electrolysis chamber, said metal strip being connected as a cathode, said plating wheel including a shaft having an axis about which said wheel rotates, an electrolyte distributor including a ring-shaped chamber surrounding said shaft and a plurality of radial channels communicating with said ring-shaped chamber and with said electrolysis chamber, and jet means disposed at the point where said radial channels communicate with said electrolysis chamber for distributing said electrolyte in jets in said electrolysis chamber.
 2. The apparatus as recited in claim 1 wherein said transport means includes means upstream of said plating wheel for regulating the tension on said metal strip.
 3. The apparatus as recited in claim 1 wherein a titanium wire is connected with said anode means and extends through said plating wheel.
 4. The apparatus as recited in claim 1 wherein said plating wheel is made of a transparent material.
 5. The apparatus as recited in claim 1 wherein said anode means is an annular platinum plated titanium annulus disposed at the point where said radial channels communicate with said electrolysis chamber.
 6. The appAratus as recited in claim 5 wherein said anode annulus has a plurality of holes therein forming jet means for said electrolyte.
 7. The apparatus as recited in claim 1 wherein said transport means includes a plurality of rollers and an endless carrier band engaging and carrying said metal strip and arranged around said rollers, said carrier band guiding said metal strip into engagement with said shoulder means to close at least said portion of said slot opening, and the side of said carrier band engaging said metal strip being made of an elastic material to prevent leakage from said electrolysis chamber.
 8. The apparatus as recited in claim 7 wherein said transport means includes means for regulating the tension on said carrier band.
 9. The apparatus as recited in claim 7 wherein said carrier band is made of a non-expandable backing coated with a layer of elastic material.
 10. The apparatus as recited in claim 7 wherein said transport means includes a drive roller rotated by a speed regulated motor to permit minimum tension on said metal strip.
 11. The apparatus as recited in claim 7 wherein said transport means includes cleaning means for rinsing said carrier band after said carrier band leaves said plating wheel to remove electrolyte therefrom.
 12. The apparatus as recited in claim 7 wherein said plating wheel includes a stationary shaft, first and second ring members mounted on bearings on said stationary shaft in spaced relation, a peripheral rim portion of said first ring member being attached to said second ring member, said rim portion having a plurality of holes therein to define said slot opening discontinuously to function as a mask for plating the metal pattern on said metal strip.
 13. The apparatus as recited in claim 10 wherein said shoulder means has indexing pins extending therefrom and said carrier band and said metal strip have holes therein to receive said indexing pins.
 14. The apparatus as recited in claim 13 wherein said rim portion of said first ring member is made of an elastic material.
 15. The apparatus as recited in claim 1 wherein said plating wheel includes a stationary shaft and said sides include a pair of ring members mounted on bearings on said shaft in spaced relation, the space between said rings defining said electrolysis chamber and said slot opening at the periphery of said rings.
 16. The apparatus as recited in claim 15 wherein said plating wheel includes a rim ring disposed between said ring members at the periphery thereof, said shoulder means and said rim ring carrying annular sealing members to form a pair of openings to permit plating of two metal patterns simultaneously.
 17. The apparatus as recited in claim 15 wherein said shaft has a bore therein and a plurality of radial holes communicating with said bore, said ring members include radially extending ribs defining a ring-shaped chamber around said shaft communicating with said radial holes and defining a plurality of radial channels communicating with said ring-shaped chambers and said electrolysis chamber, said ring members having discharge holes therein and said electrolyte means includes tank means disposed below said plating wheel to collect electrolyte, filtering and heating exchanging means, and supply means including a pump and valve means to controllably force a fluid electrolyte from said tank means through said filtering and heat exchanging means, said bore, said radial holes in said shaft, said ring-shaped chamber, said radial channels, said electrolysis chamber and said discharge holes to said tank means whereby the supply of electrolyte to said electrolysis chamber is continuously replenished.
 18. The apparatus as recited in claim 15 wherein said slot opening is radially outwardly tapered such that the width of said slot is greater adjacent said shoulder means to screen the edges of the plated metal pattern by said ring members whereby the plated metal pattern has a uniform thickness.
 19. The apparatus as rEcited in claim 15 wherein said plating wheel includes a pair of adjustment rings each carried by one of said ring members, said adjustment rings being axially adjustable along said shaft to determine the location on said metal strip of the metal pattern to be plated and to permit plating of metal strips of varying widths.
 20. The apparatus as recited in claim 19 wherein said plating wheel includes a ring-like mold element made of elastic nonconductive material and having a plurality of holes therein, said mold element engaging said metal strip and said shoulder means whereby a spotted metal pattern can be plated on said metal strip.
 21. The apparatus as recited in claim 19 wherein said adjustment rings are disposed adjacent said shoulder means to seat said metal strip on said shoulder means in fluid tight relation to seal said slot opening.
 22. The apparatus as recited in claim 21 wherein said adjustment rings each have a bevelled edge slanting toward said slot opening to seat said metal strip on said shoulder means.
 23. The apparatus as recited in claim 21 wherein said shoulder means carries annular sealing members around the periphery of said wheel on either side of said slot opening to determine the width of the metal pattern to be plated on said metal strip. 